Compressed air-driven turbines



March 4, 1958 G. c. MEREDEW ErAL 2,825,493

' coMPREssED AIR-DRIVEN TURBINES Filed Feb. l1, 1953 5 Sheets-Sheet 2March 4,'1958 G. c. MEREDEW ETAL 2,825,493

' COMPRESSED AIR-DRIVEN TURBINES Filed Feb. 11, 195s 5 sheets-sheet sMarch 4, 1958 G.' c. MEREDaw ETAL 2,825,493

coMPREssED A1R-DR1VEN TURBINES Fil-ed Feb. l1, 1953 5 Sheets-Sheet 4TZ-VEN TURS' G. c. MEREDEW ern-AL 2,825,493

coMPREssEn AIR-DRIVEN 'TURBmEs March 4, 1958 5 Sheets-Sheet 5 Filed Feb.11, 1953 Umffd .Sfere Pee-a COB/IPRESSED AIR-DRIVEN TURBINES GeorgeCharles Meredew, London, England, Kenneth Victor William Berris,Adelaide, South Australia, and Frederick Edward Samuel Smedley, Beeston,England, assignors to Bernard Bercovitz, Leaside, Ontario, Canada, andRolls-Royce Limited, Derby, England, a British company Applicationrebmery 11, 195s, serial No. 336,377

Claims priority, application Great Britain February 26, 1952 4 Claims.(Cl. 222-334) The invention relates to compressed-air-driven turbinesintended for submersion in liquids (e. g. a volatile fuel).

In practice the air supply to the turbine usually has a temperaturewhich is greater than that of the liquid and as it is necessary toconvey the air through the liquid to the submersed turbine there isusually a transfer of heat from the air to the liquid. This heattransfer is undesirable and it is an object of the invention to reduceor eliminate such transfer. To achieve this object the invention takesadvantage of the fact that the air used for driving the turbine iscooler after expansion than the incoming high pressure air.

According to the invention in one of its forms a compressed-air-driventurbine of the above kind is character-A ised by the feature that theair outlet conduit is constructed as a jacket around the turbine. Theturbine may also have air inlet and outlet conduits for conveying theinlet and outlet air through the liquid and be characterised by the factthat, in the vicinity of the turbine, the air outlet conduit isconstructed as a jacket around the air inlet conduit so that the exhaustair serves as a shroud for the incoming air and reduces or eliminatesloss of heat from the incoming air to the liquid.

In a preferred form of the invention the turbine is arranged for axialow of the air and the air leaving the turbine blades is taken in theopposite axial direction through a shroud around the outside of theturbine into the outlet conduit. It is also preferred that the inlet andexhaust conduits are separated at a fitting for attachment to a wall (e.g. the bottom) of a tank for the liquid and providing separateconnections for external pipes.

One specific construction of a turbine according to the invention andsome modifications thereof will now be described by Way of example andwith reference to the accompanying drawings in which:

Figure 1 is a section through the turbine and a part section through apump driven thereby,

Figure 2 is a plan view of the turbine and pump shown in Figure 1,

Figure 3 is a side view of the turbine and pump,

Figure 4 is a plan view of a modied form of turbine and pump, and

Figure 5 is a side view of a further modified form of turbine and pump.

The turbine forming the subject of this example is arranged to drive afuel pump constructed as described in the specification ofcontinuation-impart application No. 249,250, tiled October 2, 1951 (nowPatent No. 2,721,677), with reference to Figure 3 of the drawings. Theturbine replaces the electric motor and drives the pump spindle 14through gearing 52, 56, the axis of rotation of the turbine beingnormally horizontal. The turbine 100 is arranged for axial flow of theair in the direction towards the pump and has an annular ring of nozzles101 directing the air on to the blades 102 of the irst turbine wheel103, a fixed ring of reaction blades 104 through which the air passesafter leaving the rst turbine wheel, and a second wheel 105 havingblades 106 onto which the air is then directed. 'Ihe turbine casing isformed with an annular conduit leading to the ring of nozzles 101 andprovided with an axially directed inlet 111 on the side of the casingremote from the pump. ThisV inlet leads through a right-angle elbow 112to a. fitting 113 for attachment to the bottom wall of the tank and forconnection through the bottom to an air supply pipe 114.

At the outlet end of the turbine the casing provides an annular ring 115for the exhaust air which diverts the air through 180 outwardly into ashroud 116 around the turbine and around the air inlet 110. This shroudleads to an outlet elbow 117 which also surrounds the inlet elbow 112and is connected to the aforesaid fitting. At this fitting the exhaustshroud has a sideways extension 117a which is connected through thefitting to an independent exhaust outlet pipe 118 outside the tank.ri'he arrangement ensures that the hot incoming air is completelyshrouded from the fuel in the tank by the cooler outgoing air.

A bleed connection is provided between the inside of the turbine andgear casing and the exhaust shroud. The connection is provided by thecentral passageway through the tubular bolt 119.

The turbine is provided with a governor and control Valve as shown ormodified as described in our specification United States Patent No.2,782,001, tiled February 11, 1953. In the construction shown in thepresent drawings there is a sleeve valve 120 co-operating with ports 121to control the incoming air and there are centrifugal weights 122 whichoperate through a two-part push-rod to move the valve sleeve axially.The push rod passes through the spindle of the turbine and the part 123rotates with the spindle. The other part, 124, of the rod does notrotate `and the thrust is transmitted between the parts by a ballbearing 125. A spring 126 urges the valve against the action of theweights.

In the modified form of the above example shown in Figure 4 the elbows112 and 117 are replaced by a fitting 130 in which there is an internalair inlet pipe extending axially from the annular inlet conduit 110 toan air inlet connection 131 and the exhaust shroud surrounds the inletpipe and leads to an outlet 132. In the construction shown the fitting130 is of Y form but it may, if desired, be of T form. The fitting isoutside the tank 134, the inlet side of the turbine casing protrudingthrough an opening in a cover plate 133 for an aperture in a side wallof the tank. Alternatively the turbine casing mayabut against the coverplate and the nested tubes pass through the plate.

Figure 5 shows a further alternative in which the elbows 112 and 117 arereplaced by two straight flexible pipes and 141. The pipe 140 is theinlet pipe and the pipe 141 is the exhaust pipe. The unit shown in thisgure is supported from a plate 142 secured over an aperture in thebottom wall 143 of a tank.

The constructions forming the subject of the above examples are intendedfor use as booster pumps submerged in the fuel in fuel tanks of jetpropelled aircraft. The air for driving the turbine in such aninstallation, is derived from the jet engine and may have a temperatureof 200 C. or higher. Consequently it is important to avoid, so far as ispracticable, transfer of heat from the incoming air to the fuel.

We claim:

1. In combination with an aircraft fuel tank having a Y fuel pump fordelivering fuel from the tank, a comy 3 Y e i* i Y pressed-air-drivenVtru-bine .mounted W-ithirr'the` lztankf in driving 'connec'tionv/i'ththe pump `and located for sub-V m'ersion in theY fuel, saidtturbinecomprising a'tu'rbine rotor, .a casing around the j'rotor having nozzlesat one Vend for directtingcompressed -ainontofuthe rotor, Vancientto{ajdischarge ,conduit for thelejihaust air. v Y

v2. '.'In fcombination 'withn an aircraft fuel tank `having VVfuelfpumpffor deliv'ering fuelY from thel,tankgaafomlpressed-air-fdriven turbine as claimed -in claim l, saidthe Ysaid"dischar,ge conduit surrounding the inlet conduit.

I VVVjacket;aroundthecasingfopenftofthe outletnd'leadin'g ,Y

Y Yturbinelhavingan' airfinletV conduitleding tothe nozzles,

t 13. In' combination with 1an aircraft fuel tanklhaving aV i fuel pump'for delivering -fuel Vfrom the "tank, acom-V pressed-airrdriven-turbine mounted Within the tank 'in drivingjconne'c'tion With thepmfpand located for submersinin ',thejfu'el, sidturbine Vcornprisingiaturbine *'rotor, a casing' around kthe [rotor havingVnozzlesfforfdirecting compressed f aironto the rotor, an inlet conduitleading to lt'he nozzles andnair outlet conditleading Y 'from'theca'sing,`both saidinlet conduit and Vsaidfou'tle't Referencesjcidttntheme of'uiis parent'g U1/@IrrenSTAT-Es'V PATENTS l IGermany 77.*.; Aug.13, :1951`V

